Tessaracoccus lacteus sp. nov., Isolated from the Sludge of a Wastewater Treatment Plant

A bacterium, designated strain T21T, that is non-motile, rod-shaped, and formed pale white colonies, was isolated from the sludge of a wastewater treatment plant's secondary sedimentation tank in China. Strain T21T could grow at 20-40 °C (optimum growth at 30 °C), pH 3.0-10.0 (optimum growth at pH 5.0) and in the presence of 0-8.0% (w/v) NaCl (optimum growth at 2.0%). Based on phylogenetic analysis of 16S rRNA gene sequences and genome sequences, the isolate belongs to the genus Tessaracoccus in the phylum Actinomycetota. It exhibited a close relationship with Tessaracoccus palaemonis J1M15T, Tessaracoccus defluvii LNB-140T, Tessaracoccus flavescens SST-39T, and Tessaracoccus coleopterorum HDW20T. The 16S rRNA gene sequence similarities are 99.8%, 97.9%, 97.9%, and 97.8%, respectively. The major cellular fatty acids were anteiso-C15:0 and C16:0. The main respiratory quinone was MK-9(H4). The polar lipids included phosphatidylglycerol, diphosphatidylglycerol, glycolipid, and phospholipid. Genome annotation of strain T21T predicted the presence of 2829 genes, of which 2754 are coding proteins and 59 are RNA genes. The genomic DNA G+C content was 69.2%. Based on the results of phylogenetic, phenotypic, chemotaxonomic, and genotypic analyses, we propose the name Tessaracoccus lacteus sp. nov. for this novel species within the genus Tessaracoccus. The type strain is T21T (=CCTCC AB 2023031T = KCTC 49936T).

Discovery of a novel potential polyphosphate accumulating organism without denitrifying phosphorus uptake function in an enhanced biological phosphorus removal process

Enhanced biological phosphorus removal (EBPR) is an effective process for phosphorus removal from wastewater. In this study, two lab-scale sequencing batch reactors (SBR) were used to perform EBPR process, in which genus Propioniciclava was unexpectedly accumulated and its relative abundance was over 70 %. A series of tests were conducted to explore the role of Propioniciclava in the two EBPR systems. The two systems performed steadily throughout the study, and the phosphorus removal efficiencies were 96.6 % and 93.5 % for SBR1 and SBR2, respectively. The stoichiometric analysis related to polyphosphate accumulating organisms (PAOs) indicated that polyphosphate accumulating metabolism (PAM) was achieved in the anaerobic phase. It appeared that the Propioniciclava-dominated systems could not perform denitrifying phosphorus removal. Instead, phosphorus was released under anoxic conditions without carbon sources. According to the genomic information from Integrated Microbial Genomes (IMG) database, Propioniciclava owns ppk1, ppk2 and ppx genes that are associated with phosphorus release and uptake functions. By phylogenetic investigation of communities by reconstruction of unobserved states 2 (PICRUSt2) analysis, the abundance of genes related to phosphorus metabolism was much higher than that of genes related to denitrification. Therefore, Propioniciclava was presumed to be a potential PAO without denitrifying phosphorus uptake function. In addition to Propioniciclava, Tessaracoccus and Thiothrix were also enriched in both systems. Overall, this study proposes a novel potential PAO and broadens the understanding of EBPR microbial communities.

Tessaracoccus caeni sp. nov., a novel member of Propionibacteriaceae isolated from activated sludge in Hefei, PR China

A floc-forming bacterial strain, designated HF-7T, was isolated from the activated sludge of an industrial wastewater treatment plant in Hefei, PR China. Cells of this strain were Gram-stain-positive, catalase- and oxidase-negative, facultatively anaerobic, and rod-shaped. Growth occurred at 20-42 °C (optimum, 28 °C), at pH 5.5-10.5 (optimum, pH 7.5) and with 0-8.0 % (w/v) NaCl (optimum, 1 %). The major fatty acid was anteiso-C15 : 0. The polar lipid profile contained phosphatidylglycerol, diphosphatidylglycerol and phosphatidylinositol. The DNA G+C content was 67 mol% from whole genomic sequence analysis. Based on the results of 16S rRNA gene sequence analysis, this strain should be assigned to the genus Tessaracoccus and is closely related to Tessaracoccus arenae CAU 1319T (95.87 % similarity), Tessaracoccus lapidicaptus IPBSL-7T (95.19 %) and Tessaracoccus bendigoensis Ben 106T (94.63 %) but separated from them by large distances in different phylogenetic trees. Based on whole genome analysis, the orthologous average nucleotide identity and in silico DNA-DNA hybridization values against two of the closest relatives were 75.21-76.50 % and 14.2-24.4 %, respectively. The phylogenetic, genotypic, phenotypic and chemotaxonomic data demonstrated that strain HF-7T could be distinguished from its phylogenetically related species and represents a novel species within the genus Tessaracoccus, for which the name Tessaracoccus caeni sp. nov. is proposed. The type strain is HF-7T (=KCTC 49959T=CCTCC AB 2023019T).

Nocardioides palaemonis sp. nov. and Tessaracoccus palaemonis sp. nov., isolated from the gastrointestinal tract of lake prawn

Two novel Gram-stain-positive, non-motile and non-spore-forming bacterial strains, designated J2M5^T and J1M15^T, were isolated from the gastrointestinal tract of a lake prawn Palaemon paucidens. Strain J2M5^T was an obligately aerobic bacterium that formed milky-coloured colonies and showed a rod-coccus cell cycle, while strain J1M15^T was a facultatively aerobic bacterium that formed orangish-yellow-coloured colonies and showed rod-shaped cells. Strains J2M5^T and J1M15^T showed the highest 16S rRNA gene sequence similarity to Nocardioides ganghwensis JC2055^T (98.63 %) and Tessaracoccus flavescens SST-39^T (98.08 %), respectively. The whole-genome sequence of strain J2M5^T was 4.52 Mbp in size and the genomic G+C content directly calculated from the genome sequence of strain J2M5^T was 72.5 mol%. The whole-genome sequence of strain J1M15^T was 3.20 Mbp in size and the genomic G+C content directly calculated from the genome sequence of strain J1M15^T was 69.6mol %. Strains J2M5^T and J1M15^T showed high OrthoANI similarity to N. ganghwensis JC2055^T (83.6 %) and T. flavescens (77.2 %), respectively. We analysed the genome sequences of strains J2M5^T and J1M15^T in terms of carbohydrate-active enzymes, antibiotic resistance genes and virulence factor genes. Strains J2M5^T and J1M15^T contained MK-8 (H₄) and MK-9 (H₄) as the predominant respiratory quinones, respectively. The major polar lipids of both strains were phosphatidylglycerol and diphosphatidylglycerol. Additionally, strain J2M5^T possessed phosphatidylcholine, phosphatidylserine and phosphatidylethanolamine. The cellular sugar components of strain J2M5^T were ribose, mannose, glucose and galactose, and its cellular amino acid components were l-alanine and l-lysine. The cellular sugar components of strain J1M15^T were rhamnose, ribose, mannose and glucose, and its cellular amino acid component was l-alanine. The major cellular fatty acids of strains J2M5^T and J1M15^T were iso-C_{16 : 0} and anteiso-C_15 : 0, respectively. The multiple taxonomic analyses indicated that strains J2M5^T and J1M15^T represent novel species of the genus Nocardioides and Tessaracoccus, respectively. We propose the names Nocardioides palaemonis sp. nov. and Tessaracoccus palaemonis sp. nov. for strain J2M5^T (=KCTC 49461^T=CCUG 74767^T) and strain J1M15^T (=KCTC 49462^T=CCUG 74766^T), respectively.

Effect of external carbon addition and enrofloxacin on the denitrification and microbial community of sequencing batch membrane reactor treating synthetic mariculture wastewater

The effect of sequencing batch membrane bioreactor (SMBR) on external carbon addition and enrofloxacin was investigated to treat synthetic mariculture wastewater. Anoxic/anaerobic and low COD/TN can improve the ammonia oxidation of the system, and the NH₄⁺-N removal efficiency above 99%. External carbon was added and an anoxic environment was set to provide a suitable environment for denitrifying bacteria. When the external carbon source was 50-207 mg/L, the TN removal efficiency (31.82%-37.73%) and the COD of the effluent (28.85-36.58 mg/L) had little change. The partition resistance model showed that cake deposition resistance (R_C,irr) and irreversible resistance (R_PB) were the main components. And with the increase in cleaning times, the fouling rate of membrane components accelerated. Enrofloxacin can promote the TN removal efficiency (45.66%-93.74%) and had a significant effect on TM7a, Cohaesibacter, Vibrio and Phaeobacter.

Tessaracoccus coleopterorum sp. nov., isolated from the intestine of the dark diving beetle, Hydrophilus acuminatus

A polyphasic taxonomic approach was used to characterize a novel bacterium, designated as strain HDW20^T, isolated from the intestine of the dark diving beetle Hydrophilus acuminatus. The isolate was Gram-stain-positive, facultatively anaerobic, non-motile, coccus-shaped, and formed pale orange colonies. Phylogenetic analysis based on 16S rRNA gene sequences and genome sequences showed that the isolate belonged to the genus Tessaracoccus in the phylum Actinobacteria and was closely related to T. flavescens SST-39^T, T. defluvii JCM 17540^T, and T. aquimaris NSG39^T, with the highest 16S rRNA gene sequence similarity of 98.5 % and a highest average nucleotide identity (ANI) value of 80.6 %. The major cellular fatty acids were C_18 : 1  ω9c and anteiso-C_15 : 0. The main respiratory quinone was MK-9 (H₄). The major polar lipid components were phosphatidylglycerol and diphosphatidylglycerol. The genomic DNA G+C content was 69.0 %. The isolate contains ʟʟ-diaminopimelic acid, ʟ-alanine, and ʟ-lysine as amino acid components, and ribose, glucose, and galactose as sugar components of the cell wall peptidoglycan. The results of phylogenetic, phenotypic, chemotaxonomic, and genotypic analyses suggested that strain HDW20^T represents a novel species within the genus Tessaracoccus. We propose the name Tessaracoccus coleopterorum sp. nov. The type strain is HDW20^T (=KACC 21348^T=KCTC 49324^T=JCM 33674^T).

Marine Actinobacteria Bioflocculant: A Storehouse of Unique Biotechnological Resources for Wastewater Treatment and Other Applications

The bioactive compounds produced by actinobacteria have played a major role in antimicrobials, bioremediation, biofuels, enzymes, and anti-cancer activities. Biodegradable microbial flocculants have been produced by bacteria, algae, and fungi. Microbial bioflocculants have also attracted biotechnology importance over chemical flocculants as a result of degradability and environmentally friendly attributes they possess. Though, freshwater actinobacteria flocculants have been explored in bioflocculation. Yet, there is a paucity of information on the application of actinobacteria flocculants isolated from the marine environment. Similarly, marine habitats that supported the biodiversity of actinobacteria strains in the field of biotechnology have been underexplored in bioflocculation. Hence, this review reiterates the need to optimize culture conditions and other parameters that affect bioflocculant production by using a response surface model or artificial neural network.

Ruegeria sediminis sp. nov., isolated from tidal flat sediment

A Gram-stain-negative, aerobic, non-motile, rod-shaped bacterial strain, designated CAU 1488^T, was isolated from tidal flat sediment, and its taxonomic position was investigated using a polyphasic approach. The organism grew optimally at a temperature of 30 °C, at pH 7.0-7.5 and in the presence of 0-6 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CAU 1488^T forms a lineage distinct from Ruegeria marisrubri ZGT 118^T (97.9 %), Ruegeria marina ZH17^T (97.6 %), Ruegeria lacuscaerulensis ITI 1157^T (97.5 %), Ruegeria pomeroyi DSS-3^T (97.1 %), Ruegeria profundi ZGT108^T (97.0 %), Ruegeria intermedia CC-GIMAT-2^T (96.8 %), Ruegeria atlantica CECT 4292^T (96.7 %) and Ruegeria kandeliae J95^T (95.9 %). Genome sequencing revealed that CAU 1488^T had a genome size of 4.23 Mbp and a G+C content of 63.2 mol%. Overall genome related indexes including average nucleotide identity and digital DNA-DNA hybridization values were 75.0-83.0 % and 26.2 %, which are below the cutoffs of 95 and 70 %, respectively, indicating that strain CAU 1488^T represents a distinct species from the members of the genus Ruegeria. The predominant quinone was ubiquinone-10 (Q-10). The major fatty acids were summed feature 8 (C_18 : 1  ω7c/ω6c; 60.7 %) and its polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine and unidentified aminolipids. On the basis of phenotypic, chemotaxonomic and genomic data, strain CAU 1488^T constitutes a novel species of the genus Ruegeria, for which the name Ruegeria sediminis sp. nov. is proposed. The type strain is CAU 1488^T (=KCTC 62996^T=NBRC 113693^T).

Tessaracoccus antarcticus sp. nov., a rhodopsin-containing bacterium from an Antarctic environment and emended description of the genus Tessaracoccus

A Gram-stain-positive, facultatively anaerobic bacterium, strain JDX10T, was isolated from a soil sample of Fildes Peninsula, Antarctica. Cells of the strain were irregular rod-shaped and non-motile. Cells grew at 4–40 °C (optimum, 28 °C), at pH 6.0–9.0 (optimum, 7.5) and with 0.0–3.0 % (w/v) NaCl (optimum, 1.0 %). According to phylogenetic analysis based on 16S rRNA gene sequences, strain JDX10T was associated with the genus Tessaracoccus , and showed highest similarities to Tessaracoccus rhinocerotis CCTCC AB 2013217T (97.2 %), Tessaracoccus flavescens SST-39T (96.9 %) and Tessaracoccus terricola JCM 32157T (96.9 %). The average nucleotide identity scores of strain JDX10T to T. rhinocerotis CCTCC AB 2013217T and T. bendigoensis JCM 13525T were 74.8 and 73.3 %, respectively and the Genome-to-Genome Distance Calculator scores were 19.2 and 18.7 %, respectively. The major (>10.0 %) cellular fatty acid was anteiso-C15 : 0. The predominant isoprenoid quinone was MK-10(H4). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and one unidentified glycolipid. The phylogenetic analysis and physiological and biochemical data showed that strain JDX10T should be classified as representing a novel species in the genus Tessaracoccus , for which the name Tessaracoccus antarcticus sp. nov. is proposed. The type strain is JDX10T (=MCCC 1H00351T=KCTC 49242T).

Arcanobacterium ihumii sp. nov., Varibaculum vaginae sp. nov. and Tessaracoccus timonensis sp. nov., isolated from vaginal swabs from healthy Senegalese women

Culturomics studies the microbial variety of the human microbiome by combining diversified culture conditions, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA gene identification. This study identifies three putative new bacterial species: Arcanobacterium ihumii sp. nov. strain Marseille-P5647T, Varibaculum vaginae sp. nov. strain Marseille-P5644T and Tessaracoccus timonensis sp. nov. strain Marseille-P5995T, which we describe according to the concept of taxonogenomics.

Marine Rare Actinomycetes: A Promising Source of Structurally Diverse and Unique Novel Natural Products

Rare actinomycetes are prolific in the marine environment; however, knowledge about their diversity, distribution and biochemistry is limited. Marine rare actinomycetes represent a rather untapped source of chemically diverse secondary metabolites and novel bioactive compounds. In this review, we aim to summarize the present knowledge on the isolation, diversity, distribution and natural product discovery of marine rare actinomycetes reported from mid-2013 to 2017. A total of 97 new species, representing 9 novel genera and belonging to 27 families of marine rare actinomycetes have been reported, with the highest numbers of novel isolates from the families Pseudonocardiaceae, Demequinaceae, Micromonosporaceae and Nocardioidaceae. Additionally, this study reviewed 167 new bioactive compounds produced by 58 different rare actinomycete species representing 24 genera. Most of the compounds produced by the marine rare actinomycetes present antibacterial, antifungal, antiparasitic, anticancer or antimalarial activities. The highest numbers of natural products were derived from the genera Nocardiopsis, Micromonospora, Salinispora and Pseudonocardia. Members of the genus Micromonospora were revealed to be the richest source of chemically diverse and unique bioactive natural products.